Music of the Spheres – The Sounds of Earth’s Magnetosphere

September 18, 2012

‘Audio (wav or mp3) of the phenomenon known as “chorus” radio waves within Earth’s magnetosphere that are audible to the human ear, as recorded on Sept. 5, 2012, by RBSP’s Electric and Magnetic Field Instrument Suite and Integrated Science (EMFISIS). Five six-second “events” are captured in this sample, and they are played end-to-end, one right after the other, without gaps. Credit: University of Iowa

Researchers from the Electric and Magnetic Field Instrument Suite and Integrated Science (EMFISIS) team at the University of Iowa have released a new recording of an intriguing and well-known phenomenon known as “chorus,” made on Sept. 5, 2012. The Waves tri-axial search coil magnetometer and receiver of EMFISIS captured several notable peak radio wave events in the magnetosphere that surrounds the Earth. The radio waves, which are at frequencies that are audible to the human ear, are emitted by the energetic particles in the Earth’s magnetosphere.

“People have known about chorus for decades,” says EMFISIS principal investigator Craig Kletzing, of the University of Iowa. “Radio receivers are used to pick it up, and it sounds a lot like birds chirping. It was often more easily picked up in the mornings, which along with the chirping sound is why it’s sometimes referred to as ‘dawn chorus.’”

This recording was made by many members of the EMFISIS team, including Terry Averkamp, Dan Crawford, Larry Granroth, George Hospodarsky, Bill Kurth, Jerry Needell and Chris Piker.

I know from my amateur radio days that we could sometimes hear “whistlers”, signals from ionized trains behind meteoroids. One could transmit over great distances by sending a radio signal toward a meteor shower and hear this phenomenon

Yes, I remember that as well. When were you active? Many lifetimes ago I was G3PUK back in England. Now a Brit living in Arizona and en-route to living in Oregon. Technically, I still have a valid British licence but when I tell you that my final amplifier was a pair of 807s driving an 813 you will understand how long ago this was! 😉